Hi Super Frog
I'm not with Laminar Research, just a fellow simmer in the UK.
I suspect that the King Air 350 that your purchased was originally produced by Airfoillabs, so I'm not sure if your got it directly from them or through X-Plane.org?
Either way, I would suggest that you try re-downloading the relevant aircraft files again, as clearly it seems as though you have a couple missing.
Regards